Flexible touch screen panel and flexible display device with the same

ABSTRACT

A flexible touch screen panel includes a thin film substrate divided into an active area and a non active area positioned at the outside of the active area; sensing patterns formed on the active area of a first surface of the thin film substrate, including first sensing cells formed to be connected along a first direction and second sensing cells formed to be connected along a second direction; and sensing lines formed on the non active area of the first surface of the thin film substrate. The sensing lines are connected to the sensing patterns. In the touch screen panel, the area and/or interval of the sensing cells formed on a first region, which is capable of being bent by predetermined curvature about a folding axis is different from the area and/or interval of the sensing cells formed on a second region as a flat region except the first region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. patent application Ser. No.15/245,785, filed on Aug. 24, 2016, which is a Division of U.S. patentapplication Ser. No. 13/776,932, filed on Feb. 26, 2013, which claimspriority to and the benefit of Korean Patent Application No.10-2012-0128722, filed on Nov. 14, 2012, each of which is herebyincorporated by reference for all purpose as if fully set forth herein.

BACKGROUND Field

An aspect of the present invention relates to a touch screen panel, andmore particularly, to a flexible touch screen panel and a flexibledisplay device with the same.

Description of the Related Art

A touch screen panel is an input device that allows a user's instructionto be inputted by selecting an instruction content displayed on a screenof an image display device or the like with a user's hand or object.

To this end, the touch screen panel is formed on a front face of theimage display device to convert a contact position into an electricalsignal. Here, the user's hand or object is directly in contact with thetouch screen panel at the contact position. Accordingly, the instructioncontent selected at the contact position is inputted as an input signalto the image display device.

Since such a touch screen panel can be substituted for a separate inputdevice connected to an image display device, such as a keyboard ormouse, its application fields have been gradually extended.

Touch screen panels are divided into a resistive overlay touch screenpanel, a photosensitive touch screen panel, a capacitive touch screenpanel, and the like. Among these touch screen panels, the capacitivetouch screen panel converts a contact position into an electrical signalby sensing a change in capacitance formed between a conductive sensingpattern and an adjacent sensing pattern, ground electrode or the likewhen a user's hand or object is in contact with the touch screen panel.

Generally, such a touch screen panel is frequently commercialized bybeing attached to an outer face of a flat panel display device such as aliquid crystal display device or organic light emitting display device.Therefore, the touch screen panel requires characteristics of hightransparency and thin thickness.

A flexible image display device has recently been developed, and in thiscase, a touch screen panel attached on the flexible image display devicealso requires flexibility.

However, in the related art capacitive touch screen panel, sensingpatterns, etc. are generally formed on a glass substrate, and the glasssubstrate should have no less than a predetermined thickness to beconveyed in processes. Therefore, the glass substrate does not satisfythe thin characteristic required in the touch screen panel, and cannotimplement the flexibility.

SUMMARY

Embodiments provide a flexible touch screen panel having sensingpatterns as touch sensors formed on a thin film substrate havingflexibility, in which the area and/or interval of the sensing cellsformed on a first region having a predetermined curvature based on afolding axis about which the touch screen panel is bent and the sensingcells formed on a second region as a flat region except the first regionare controlled, so that it is possible to minimize the difference intouch sensitivity between the first and second regions, therebyimproving the accuracy and precision of touch recognition.

Embodiments also provide a flexible display device having the flexibletouch screen panel described above.

According to an aspect of the present invention, there is provided aflexible touch screen panel, including: a thin film substrate includingan active area and a non active area positioned at the outside of theactive area; sensing patterns formed on the active area of a firstsurface of the thin film substrate, and including first sensing cellsformed to be connected along a first direction and second sensing cellsformed to be connected along a second direction; and sensing linesformed on the non active area of the first surface of the thin filmsubstrate, and connected to the sensing patterns. The flexible touchscreen panel has a first region, which is capable of being bent by apredetermined curvature about a folding axis, and a second region as aflat region, areas of the sensing cells formed on the first region beingdifferent from areas of the sensing cells formed on the second region,or an interval between two of the sensing cells formed on the firstregion being different from an interval between two of the sensing cellsformed on the second region.

When the thin film substrate having the sensing cells formed thereon isbent in the opposite direction to the first surface thereof, theinterval between the first and second sensing cells formed on the firstregion may be smaller than that between the first and second sensingcells formed on the second region, or the area of the first and secondsensing cells formed on the first region may be larger than that of thefirst and second sensing cells formed on the second region.

When the thin film substrate having the sensing cells formed thereon isbent in the direction of the first surface thereof, the interval betweenthe first and second sensing cells formed on the first region may belarger than that between the first and second sensing cells formed onthe second region, or the area of the first and second sensing cellsformed on the first region may be smaller than that of the first andsecond sensing cells formed on the second region.

The sensing patterns may further include first connecting linesconnecting adjacent first sensing cells, and second connecting linesconnecting adjacent second sensing cells. An insulation layer may beinterposed between the first connecting lines and the second connectinglines.

The first and second sensing patterns may be formed in different layers.The first sensing cells may be formed on the first surface of the thinfilm substrate, and the second sensing cells may be formed in thedirection intersecting the first sensing cells on the insulation layerformed on the first surface of the thin film substrate having the firstsensing cells.

The first sensing cells may be arranged in the direction parallel withthe folding axis, and the area and interval of the first sensing cellsformed on the first region may be different from those of the firstsensing cells formed on the second region.

Each of the first sensing cells formed on the first region may bedivided into a plurality of divided sensing cells, and the area andinterval of the divided sensing cells may be formed smaller than thoseof the first sensing cells formed on the second region.

The first sensing cells arranged in the first direction may be made ofindium tin oxide (ITO), and the second sensing cells arranged in thesecond direction may be made of silver nano-wires.

The thin film substrate may be made of a polyimide material. Thethickness of the thin film substrate may be about 0.005 mm to 0.05 mm.

According to an aspect of the present invention, there is provided aflexible display device including: a thin film substrate divided into anactive area and a non active area positioned at the outside of theactive area; sensing patterns formed on the active area of a firstsurface of the thin film substrate, and including first sensing cellsformed to be connected along a first direction and second sensing cellsformed to be connected along a second direction; sensing lines formed onthe non active area of the first surface of the thin film substrate, andconnected to the sensing patterns; and a display device is attached tothe thin film substrate so as to face the sensing patterns and thesensing lines formed on the first surface of the thin film substrate.The flexible display device has a first region, which is capable ofbeing bent by a predetermined curvature about a folding axis, and asecond region as a flat region, areas of the sensing cells formed on thefirst region being different from areas of the sensing cells formed onthe second region, or an interval between two of the sensing cellsformed on the first region being different from an interval between twoof the sensing cells formed on the second region.

The display device may include an organic light emitting display device.

A polarizing film and a window substrate may be sequentially attached toa second surface of the thin film substrate through a transparentadhesive. The window substrate may be formed of at least one ofpolymethyl methacrylate (PMMA), acryl and polyester (PET).

As described above, according to the present invention, the area and/orinterval of the sensing cells formed on a first region having apredetermined curvature based on a folding axis about which the touchscreen panel is bent and the sensing cells formed on a second region asa flat region except the first region are controlled, so that it ispossible to minimize the difference in touch sensitivity between thefirst and second regions, thereby improving the accuracy and precisionof touch recognition.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, together with the specification, illustrateexemplary embodiments of the present invention, and, together with thedescription, serve to explain the principles of the present invention.

FIG. 1 is a plan view schematically showing a flexible touch screenpanel according to an embodiment of the present invention.

FIG. 2 is a main part enlarged view showing an example of a sensingpattern shown in FIG. 1.

FIGS. 3A and 3B are views showing structures of sensing cells shown inFIG. 1 when a curved surface is formed toward the outside of the sensingcells.

FIGS. 4A and 4B are views showing structures of the sensing cells shownin FIG. 1 when a curved surface is formed toward the inside of thesensing cells.

FIG. 5 is a sectional view showing one region (I-I′) of a touch screenpanel and a flexible display device with the same according to anembodiment of the present invention.

FIG. 6 is a plan view schematically showing one region of a flexibletouch screen panel according to another embodiment of the presentinvention.

DETAILED DESCRIPTION

In the following detailed description, only certain exemplaryembodiments of the present invention have been shown and described,simply by way of illustration. As those skilled in the art wouldrealize, the described embodiments may be modified in various differentways, all without departing from the spirit or scope of the presentinvention. Accordingly, the drawings and description are to be regardedas illustrative in nature and not restrictive. In addition, when anelement is referred to as being “on” another element, it can be directlyon the another element or be indirectly on the another element with oneor more intervening elements interposed therebetween. Also, when anelement is referred to as being “connected to” another element, it canbe directly connected to the another element or be indirectly connectedto the another element with one or more intervening elements interposedtherebetween. Hereinafter, like reference numerals refer to likeelements.

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a plan view schematically showing a flexible touch screenpanel according to an embodiment of the present invention. FIG. 2 is amain part enlarged view showing an example of a sensing pattern shown inFIG. 1.

Referring to FIGS. 1 and 2, the touch screen panel according to thisembodiment includes a thin film substrate 10 divided into an active areaand a non active area positioned at the outside of the active area, andhaving flexibility; sensing patterns 220 formed on the active area of afirst surface of the thin film substrate 10; and sensing lines 230formed on the non active area of the first surface of the thin filmsubstrate 10, and connecting the sensing patterns 220 to an externaldriving circuit (not shown) through a pad portion 250.

The thin film substrate 10 having the flexibility is implemented using amaterial having high thermal resistance and chemical resistance. In thisembodiment, a case where polyimide (PI) is used as the material of thethin film substrate 10 will be described as an example.

That is, the touch screen panel according to this embodiment does notuse an existing rigid material (e.g., glass, polyethylene terephthalate(PET), polycarbonate (PC), etc.) but uses the PI having the mostexcellent thermal resistance as material of the thin film substrate 10.

In this case, the thickness of the thin film substrate 10 may be about0.005 mm to 0.05 mm, preferably about 0.01 mm (10 μm), thereby securingflexibility. That is, the thin film substrate 10 having the flexibilitycan be bent, unlike the existing glass substrate.

As shown in FIG. 2, the sensing patterns 220 formed on the active areainclude a plurality of first sensing cells 220 a formed to be connectedfor each row line along a row direction (first direction), a pluralityof first connecting lines 220 a 1 connecting the first sensing cells 220a along the row direction, a plurality of second sensing cells 220 bformed to be connected for each column line along a column direction(second direction), and a plurality of second connecting lines 220 b 1connecting the second sensing cells 220 b along the column direction.

The first sensing cells 220 a and the second sensing cells 220 b arealternately arranged so as not to overlap with each other, and the firstconnecting lines 220 a 1 and the second connecting lines 220 b 1intersect each other. In this case, an insulation layer (element 270shown in FIG. 5) for securing insulation is interposed between the firstconnecting lines 220 a 1 and the second connecting lines 220 b 1.

Meanwhile, the first sensing cells 220 a may be integrally formed withthe first connecting lines 220 a 1 using a transparent conductivematerial such as indium tin oxide (hereinafter, referred to as ITO) ormay be formed separately from the first connecting lines 220 a 1 so thatthe first sensing cells 220 a and the first connecting lines 220 a 1 areelectrically connected to each other. The second sensing cells 220 b maybe integrally formed with the second connecting lines 220 b 1 using atransparent conductive material such as ITO or may be formed separatelyfrom the second connecting lines 220 b 1 so that the second sensingcells 220 b and the second connecting lines 220 b 1 are electricallyconnected to each other.

For example, the second sensing cells 220 b are integrally formed withthe second connecting lines 220 b 1 by being patterned in the columndirection. The first sensing cells 220 a are patterned to respectivelyindependent patterns between the second sensing cells 220 b, and may beconnected along the row direction by the first connecting lines 220 a 1positioned above or below the first sensing patterns 220 a.

In this case, the first connecting lines 220 a 1 may be electricallyconnected to the first sensing cells 220 a by being directly contactedwith the first sensing cells 220 a above or below the first sensingcells 220 a. Alternatively, the first connecting lines 220 a 1 may beelectrically connected to the first sensing cells 220 a through contactholes, etc.

The first connecting lines 220 a 1 may be formed using a transparentconductive material such as ITO or using an opaque low-resistance metalmaterial. The first connecting lines 220 a 1 may be formed by adjustingtheir width, etc. so that the visibility of the patterns is prevented.

The sensing lines 230 shown in FIG. 1 are electrically connected to rowlines of the first sensing cells 220 a and column lines of the secondsensing cells 220 b, respectively, so as to connect the row and columnlines to the external driving circuit (not shown) such as a positiondetecting circuit through the pad portion 250.

The sensing lines 230 are arranged on the non active area formed at theoutside of the active area in which an image is displayed. Since thematerial of the sensing lines 230 is selected in a wide range, thesensing lines 230 may be formed of not only a transparent electrodematerial used to form the sensing patterns 220 but also a low-resistancemetallic material such as molybdenum (Mo), silver (Ag), titanium (Ti),copper (Cu), aluminum (Al) or Mo/Al/Mo.

The touch screen panel according to this embodiment described above is acapacitive touch screen panel. If a contact object such as a user'sfinger or stylus pen comes in contact with the touch screen panel, achange in capacitance caused by a contact position is transferred fromthe sensing patterns 220 to the driving circuit (not shown) via thesensing lines 230 and the pad portion 250. Then, the change incapacitance is converted into an electrical signal by X and Y inputprocessing circuits (not shown), thereby detecting the contact position.

The related art touch screen panels is implemented into a structure inwhich the sensing patterns shown in FIG. 2 are repetitively arrangedwith the same area at the same interval on the active area.

However, in the touch screen panel according to this embodiment, thethin film substrate 10 has the flexibility, and accordingly, the touchscreen panel can be divided into a first region having a predeterminedcurvature based on a folding axis shown in FIG. 1, and a second regionas a flat region except the first region. In other words, the firstregion is capable of being bent or folded about the folding axis.

In a case where the sensing patterns are repetitively arranged with thesame area at the same interval on the active area, like those in therelated art touch screen panel, regardless of the first and secondregions, the area of sensing cells and the interval between the sensingcells formed on the first region having the predetermined curvature aredifferent from the area of sensing cells and the interval between thesensing cells formed on the second flat region. As a result, thecapacitance sensed in the sensing patterns formed on the first region isdifferent from that sensed in the sensing patterns formed on the secondregion.

That is, in a case where the sensing patterns having the same structureas those in the related art touch screen panel are arranged on the thinfilm substrate 10, the touch sensitivity in the first region as thecurved region is different from that in the second region as the flatregion, and therefore, driving performance such as accuracy andprecision of touch recognition may be degraded.

In order to solve such a problem, in this embodiment, the areas and/orintervals of the sensing cells formed on the first region having thepredetermined curvature based on the folding axis about which theflexible touch screen panel is bent and the sensing cells formed on thesecond region as the flat region except the first region are adjusted,so that it is possible to minimize the difference in touch sensitivitybetween the first and second regions, thereby improving the accuracy andprecision of touch recognition.

Hereinafter, the structures and arrangements of the sensing cellsaccording to this embodiment will be described in detail with referenceto FIGS. 3 and 4.

Here, the touch screen panel may be bent in the direction where a curvedsurface is formed toward the outside of the thin film substrate 10having the sensing cells formed thereon, or may be bent in the oppositedirection, i.e., the direction where a curved surface is formed towardthe inside of the thin film substrate 10 having the sensing cells formedthereon.

In other words, the touch screen panel may be bent in the oppositedirection to the first surface of the thin film substrate having thesensing cells formed thereon, or may be bent in the direction of thefirst surface of the thin film substrate having the sensing cells formedthereon. Hereinafter, the structures and arrangements of the sensingcells when the touch screen panel is bent in different directions willbe described in detail.

FIGS. 3A and 3B are views showing structures of sensing cells shown inFIG. 1 when a curved surface is formed toward the outside of the sensingcells (in the opposite direction to the first surface of the thin filmsubstrate).

That is, in the embodiment shown in FIG. 3, the touch screen panel isbent in the direction where a curved surface is formed toward theoutside of the thin film substrate 10 having the sensing cells formedthereon.

First, referring to FIG. 3A, there are shown first sensing cells 220 a′and second sensing cells 220 b′ adjacent to the first sensing cells 220a′, which are formed on a first region having a predetermined curvatureby bending the thin film substrate 10, and first sensing cells 220 a″and second sensing cells 220 b″ adjacent to the first sensing cells 220a″, which are formed on a second region as a flat region.

If the thin film substrate 10 is bent as described above, the surface ofthe thin film substrate 10, corresponding to the first region as thecurved region, becomes wider than the rest of the thin film substrate10, corresponding to the second region as the flat region, according tothe flexibility of the thin film substrate 10.

That is, if the sensing cells are repetitively arranged with the samearea at the same interval, regardless of the first and second regions,the interval between the first and second sensing cells 220 a′ and 220b′ formed on the first region becomes wider than that between the firstand second sensing cells 220 a″ and 220 b″ formed on the second regionwhen the thin film substrate 10 is bent as shown in FIG. 3A, whichresults in the occurrence of a difference between capacitancesrespectively sensed in the sensing patterns on the first and secondregions.

In order to solve such a problem, in the embodiment shown in FIG. 3A,the interval (first interval) d1 between the first and second sensingcells 220 a′ and 220 b′ formed on the first region is formed narrowerthan that (second interval) d2 between the first and second sensingcells 220 a″ and 220 b″ formed on the second region. According to thestructure described above, it is possible to minimize the differencebetween the capacitances respectively sensed in the sensing cells formedon the first and second regions.

In this case, the difference between the first and second intervals(d2−d1) corresponds to the degree at which the outer surface of the thinfilm substrate is enlarged by the bending of the thin film substrate,which can be optimized through several experiments.

Next, referring to FIG. 3B, there are shown first sensing cells 220 a′and second sensing cells 220 b′ adjacent to the first sensing cells 220a′, which are formed on a first region having a predetermined curvatureby bending the thin film substrate 10, and first sensing cells 220 a″and second sensing cells 220 b″ adjacent to the first sensing cells 220a″, which are formed on a second region as a flat region.

If the thin film substrate 10 is bent in the direction where a curvedsurface is formed toward the outside of the thin film substrate 10having the sensing cells formed thereon as described above, the areawhere the sensing cell 220 a′ or 220 b′ positioned on the first regionas the curved region is touched to the first region by the radius of thecurved surface, i.e., the curvature becomes narrower than that where thesensing cell 220 a″ or 220 b″ positioned on the second region as theflat region is touched to the second region.

That is, if the sensing cells are repetitively arranged with the samearea at the same interval, regardless of the first and second regions,the contact area of the first or second sensing cell 220 a′ or 220 b′positioned on the first region becomes narrower that of the first orsecond sensing cell 220 a″ or 220 b″ when the thin film substrate 10 isbent as shown in FIG. 3B, which results in the occurrence of adifference between capacitances respectively sensed in the sensingpatterns on the first and second regions.

In order to solve such a problem, in the embodiment shown in FIG. 3B,the area (first area) S1 of the first or second sensing cell 220 a′ or220 b′ formed on the first region is formed larger than that (secondarea) S2 of the first or second sensing cell 220 a″ or 220 b″ formed onthe second region. According to the structure described above, it ispossible to minimize the difference between the capacitancesrespectively sensed in the sensing cells formed on the first and secondregions. In this case, the difference between the first and second areas(S1−S2) can be optimized through several experiments.

FIGS. 4A and 4B are views showing structures of the sensing cells shownin FIG. 1 when a curved surface is formed toward the inside of thesensing cells.

That is, in the embodiment shown in FIGS. 4A and 4B, the touch screenpanel is bent in the direction where a curved surface is formed towardthe inside of the thin film substrate 10 having the sensing cells formedthereon (in the direction to the first surface of the thin filmsubstrate).

First, referring to FIG. 4A, there are shown first sensing cells 220 a′and second sensing cells 220 b′ adjacent to the first sensing cells 220a′, which are formed on a first region having a predetermined curvatureby bending the thin film substrate 10, and first sensing cells 220 a″and second sensing cells 220 b″ adjacent to the first sensing cells 220a″, which are formed on a second region as a flat region.

If the thin film substrate 10 is bent as described above, the intervalbetween the first and second sensing cells 220 a′ and 220 b′ formed onthe first region becomes narrower than that between the first and secondsensing cells 220 a″ and 220 b″ formed on the second region according tothe flexibility of the thin film substrate 10, which results in theoccurrence of a difference between capacitances respectively sensed inthe sensing patterns on the first and second regions.

In order to solve such a problem, in the embodiment shown in FIG. 4A,the interval (third interval) d3 between the first and second sensingcells 220 a′ and 220 b′ formed on the first region is formed larger thanthat (fourth interval) d4 between the first and second sensing cells 220a″ and 220 b″ formed on the second region. According to the structuredescribed above, it is possible to minimize the difference between thecapacitances respectively sensed in the sensing cells formed on thefirst and second regions.

In this case, the difference between the third and fourth intervals(d3−d4) corresponds to the degree at which the outer surface of the thinfilm substrate is enlarged by the bending of the thin film substrate,which can be optimized through several experiments.

Next, referring to FIG. 4B, there are shown first sensing cells 220 a′and second sensing cells 220 b′ adjacent to the first sensing cells 220a′, which are formed on a first region having a predetermined curvatureby bending the thin film substrate 10, and first sensing cells 220 a″and second sensing cells 220 b″ adjacent to the first sensing cells 220a″, which are formed on a second region as a flat region.

If the thin film substrate 10 is bent in the direction where a curvedsurface is formed toward the inside of the thin film substrate 10 havingthe sensing cells formed thereon as described above, the area where thesensing cell 220 a′ or 220 b′ positioned on the first region as thecurved region is touched to the first region by the radius of the curvedsurface, i.e., the curvature is broader than that where the sensing cell220 a″ or 220 b″ positioned on the second region as the flat region istouched to the second region.

That is, if the sensing cells are repetitively arranged with the samearea at the same interval, regardless of the first and second regions,the contact area of the first or second sensing cell 220 a′ or 220 b′positioned on the first region becomes broader than that of the first orsecond sensing cell 220 a″ or 220 b″ when the thin film substrate 10 isbent as shown in FIG. 4B, which results in the occurrence of adifference between capacitances respectively sensed in the sensingpatterns on the first and second regions.

In order to solve such a problem, in the embodiment shown in FIG. 4B,the area (third area) S3 of the first or second sensing cell 220 a′ or220 b′ formed on the first region is formed smaller than that (fourtharea) S4 of the first or second sensing cell 220 a″ or 220 b″ formed onthe second region. According to the structure described above, it ispossible to minimize the difference between the capacitancesrespectively sensed in the sensing cells formed on the first and secondregions. In this case, the difference between the third and fourth areas(S4-S3) can be optimized through several experiments.

FIG. 5 is a sectional view showing one region (I-I′) of a touch screenpanel and a flexible display device with the same according to theembodiment of the present invention.

FIG. 5 is a sectional view showing portions of an active area and a nonactive area, which are formed on a first surface of a thin filmsubstrate 10 in the touch screen panel, and shows a section of theflexible display device with the flexible touch screen panel.

Here, the flexible touch screen panel shown in FIG. 5 is the same asthat described with reference to FIGS. 1 to 4, and therefore, itsdetailed description will be omitted.

The thin film substrate 10 is implemented using a material having highthermal resistance and chemical resistance, and polyimide (PI) may beused as the material of the thin film substrate 10.

In FIG. 5, there is shown a structure in which a display device 20 isattached to the lower surface of the touch screen panel, i.e., in thedirection of the first surface of the thin film substrate 10 by atransparent adhesive layer 260. Here, the display device 20 is a displaydevice having flexibility, and may be implemented as an organic lightemitting display device.

For example, the organic light emitting display device is aself-luminescent device, and does not require a backlight unit, unlikeexisting liquid crystal display devices. Thus, in the organic lightemitting display device can have flexibility by forming a substrateusing polymethyl methacrylate (PMMA), acryl, polyester (PET), etc.

Here, the transparent adhesive layer 260 may be made of a transparentadhesive material having high light transmittance, such as a super viewresin (SVR) or optical cleared adhesive (OCA).

As shown in this figure, the touch screen panel is implemented into astructure in which a polarizing film 30 and a window substrate 40 arestacked in the direction of a second surface of the thin film substrate10. The polarizing film 30 and the window substrate 40 are attached toeach other by the transparent adhesive layer 260.

Referring to FIG. 5, sensing patterns 220 formed on the active area ofthe thin film substrate 10 include first sensing cells 220 a formed tobe connected for each row line along a row direction (first direction),first connecting lines 220 a 1 connecting the first sensing cells 220 aalong the row direction, second sensing cells 220 b formed to beconnected for each column line along a column direction (seconddirection), and second connecting lines 220 b 1 connecting the secondsensing cells 220 b along the column direction. An insulation layer 270is interposed between the first connecting lines 220 a 1 and the secondconnecting lines 220 b 1.

In FIG. 5, the thickness of each component such as the sensing patterns220, included in the touch screen panel, is exaggerated for convenienceof illustration. However, the thickness of each practical component isfar thinner than the exaggerated thickness.

As shown in this figure, a black matrix 210 and sensing lines 230 areformed on the non active area positioned at the outside of the activearea. Here, the sensing lines 230 are formed to overlap with the blackmatrix 210, and are electrically connected to the sensing patterns 220.

In this case, the black matrix 210 performs a function of forming theframe of a display area while preventing the visibility of patterns suchas sensing lines formed on the non active area.

According to the structure described above, the touch screen panel ispositioned between the display device 20 and the polarizing film 30, sothat it is possible to preventing the visibility of the sensing patternsand to minimize reflexibility while maintaining flexibility.

The window substrate 40 attached to a top surface of the polarizing film30 so as to enhance the strength of the device also has the flexibilityof the display device 20 and the touch screen panel. Therefore, thewindow substrate 40 is preferably formed of a material havingflexibility.

Accordingly, in this embodiment, the window substrate 40 may be made ofa material such as PMMA, acryl or PET, and the thickness of the windowsubstrate 40 may be about 0.7 mm.

In the embodiment described with reference to FIGS. 1 to 5, the sensingpatterns 220 of the touch screen panel are formed on the same layer asthe first and second diamond-shaped sensing cells 220 a and 220 b, andthe insulation layer 270 is interposed between the first and secondconnecting lines 220 a 1 and 220 b 1 respectively connecting the firstand second sensing cells 220 a and 220 b.

However, the sensing patterns of the touch screen panel according tothis embodiment are not limited to the structure described above, andthe first and second sensing cells 220 a and 220 b may be formed indifferent layers. In this case, the first sensing cells 220 a are formedon the first surface of the thin film substrate 10, and the insulationlayer 270 is formed on the first surface of the thin film substrate 10including the first sensing cells 220 a. The second sensing cells 220 bare formed on the insulation layer 270 in the direction where the secondsensing cells 220 b intersect the first sensing cells 220 a.

In a case where the first and second sensing cells 220 a and 220 b areformed in different layers, the first and second sensing cells 220 a and220 b may be formed in a bar shape, as well as the diamond shape. Here,the separate first and second connecting lines 220 a 1 and 220 b 1 areunnecessarily provided.

Hereinafter, an embodiment in which sensing patterns of a touch screenpanel are formed in a rod shape in different layers will be described indetail with reference to FIG. 6.

FIG. 6 is a plan view schematically showing one region of a flexibletouch screen panel according to another embodiment of the presentinvention.

In this embodiment, components identical to those of the embodimentshown in FIG. 1 are designated by like reference numerals, and theirdetailed descriptions will be omitted.

Referring to FIG. 6, the touch screen panel according to this embodimentincludes a thin film substrate 10 divided into an active area and a nonactive area positioned at the outside of the active area, and havingflexibility; sensing patterns 320 formed on the active area of a firstsurface of the thin film substrate 10; and sensing lines 230 formed onthe non active area of the first surface of the thin film substrate 10,and connecting the sensing patterns 320 to an external driving circuit(not shown) through a pad portion (not shown).

As shown in this figure, the sensing patterns 320 formed on the activearea include a plurality of first sensing cells 320 a formed to beconnected for each row line along a row direction (first direction), anda plurality of second sensing cells 320 b formed to be connected foreach column line along a column direction (second direction).

The first and second sensing cells 320 a and 320 b may be formed indifferent layers. In this case, the first sensing cells 320 a are formedon the first surface of the thin film substrate 10, and an insulationlayer (not shown) is formed on the first surface of the thin filmsubstrate 10 including the first sensing cells 320 a. The second sensingcells 320 b are formed on the insulation layer in the direction wherethe second sensing cells 320 b intersect the first sensing cells 320 a.

That is, unlike the embodiment shown in FIG. 1, the separate connectinglines 220 a 1 and 220 b 1 are unnecessarily in the embodiment shown inFIG. 6.

However, in the embodiment shown in FIG. 6, the thin film substrate 10has flexibility, and accordingly, the touch screen panel is divided intoa first region having a predetermined curvature based on a folding axisshown in FIG. 6, and a second region as a flat region except the firstregion.

As shown in this figure, the area and interval of the sensing cellsformed on the first region having the predetermined curvature based onthe folding axis about which the flexible touch screen panel is bent areimplemented differently from those of the sensing cells formed on thesecond region as a flat region except the first region. Accordingly, itis possible to minimize the difference in touch sensitivity between thefirst and second regions, thereby improving the accuracy and precisionof touch recognition.

More specifically, when assuming that the folding axis is formed in thefirst direction, the area and interval of first sensing cells 320 a′arranged in the direction parallel with the folding axis on the firstregion are implemented differently from those of the first sensing cells320 a arranged on the second region.

Particularly, each of the first sensing cells 320 a′ formed on a regionintersected by the folding axis in the first region is divided into aplurality of divided sensing cells 322 a. When comparing the dividedsensing cells 322 a in the first region with the first sensing cells 320a formed on the second region, the area and interval of the sensingcells 322 a are formed smaller than those of the first sensing cells 320a.

Here, the divided sensing cells 322 a perform an operation as one firstsensing cell 320 a′, and thus are connected to one sensing line 230 asshown in this figure.

Although the first sensing cells 320 a and 320 a′ arranged in the firstdirection are formed using a transparent conductive material such asITO, each of the first sensing cells 320 a′ arranged on the first regionas the curved region is divided into the plurality of sensing cells 322a, and the area and interval of the sensing cells 322 a are formedsmaller than those of the first sensing cells 320 a. Accordingly, it ispossible to prevent a failure such as a crack caused by the bending ofthe touch screen panel.

However, in a case where the plurality of second sensing cells 320 barranged in the second direction intersecting the folding axis areformed using the same ITO, there may occur a failure such as a crackcaused by the bending of the touch screen panel.

Accordingly, in this embodiment, the second sensing cells 320 b areimplemented as silver nano-wires (AgNW) using a transparent conductivematerial with excellent bendability.

Although not shown in FIG. 6, the active area is divided into two activeareas, and first sensing lines (not shown) extracted from a first activearea are connected to a first pad portion (not show) provided at a lowerend of the non active area and second sensing lines (not shown)extracted from a second active area are connected to a second padportion (not show) provided at an upper end of the non active area.Thus, there exists no region where the sensing lines intersect thefolding axis, so that it is possible to prevent damage of the sensinglines even when the touch screen panel is repetitively bent based on thefolding axis.

While the present invention has been described in connection withcertain exemplary embodiments, it is to be understood that the inventionis not limited to the disclosed embodiments, but, on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the spirit and scope of the appended claims, andequivalents thereof.

What is claimed is:
 1. A flexible touch screen panel, comprising: a thinfilm substrate including an active area and a non active area positionedat the outside of the active area, the thin film substrate having atleast two second regions and a first region that is disposed between thetwo second regions adjacent to each other; sensing patterns formed onthe active area of a first surface of the thin film substrate, andincluding first sensing cells arranged along a first direction andsecond sensing cells arranged along a second direction; and sensinglines formed on the non active area of the first surface of the thinfilm substrate, and electrically connected to the sensing patterns,wherein the flexible touch screen panel has a folding axis about whichthe flexible touch screen panel is bent and the folding axis is disposedin the first region, wherein when the flexible touch screen panel isbent about the folding axis, the first region forms a curvature and thesecond regions maintains a flat without a curvature, wherein an intervalbetween the first and second sensing cells adjacent to each other in thefirst region is different from an interval between the first and secondsensing cells adjacent to each other in the second regions when theflexible touch screen panel is in a non-bent state, and wherein theinterval between the first and second sensing cells in the first regionis smaller when the flexible touch screen panel is in a bent state thanwhen the flexible touch screen panel is in a non-bent state.
 2. Theflexible touch screen panel of claim 1, wherein the flexible touchscreen panel is capable of being bent such that portions of the firstsurface face each other.
 3. The flexible touch screen panel of claim 1,wherein the interval between the nearest first sensing cell and secondsensing cell formed on the first region is larger than the intervalbetween the nearest first sensing cell and second sensing cell formed onthe second regions.
 4. The flexible touch screen panel of claim 1,wherein the first sensing cells and the second sensing cells aredisposed on the same layer.
 5. The flexible touch screen panel of claim4, wherein the first sensing cells are electrically connected to eachother by first connecting lines, and the first sensing cells and thefirst connecting lines are disposed on different layers.
 6. A flexibletouch screen panel comprising: a thin film substrate including an activearea and a non active area positioned at the outside of the active area,the thin film substrate having at least two second regions and a firstregion that is disposed between the two second regions adjacent to eachother; sensing patterns formed on the active area of a first surface ofthe thin film substrate, and including first sensing cells arrangedalong a first direction and second sensing cells arranged along a seconddirection; and sensing lines formed on the non active area of the firstsurface of the thin film substrate, and electrically connected to thesensing patterns, wherein the flexible touch screen panel has a foldingaxis about which the flexible touch screen panel is bent and the foldingaxis is disposed in the first region, wherein when the flexible touchscreen panel is bent about the folding axis, the first region forms acurvature and the second regions maintains a flat without a curvature,wherein areas of the first and second sensing cells formed on the firstregion are different from areas of the first and second sensing cellsformed on the second region when the flexible touch screen panel is in anon-bent state, and wherein areas of the first and second sensing cellsformed on the first region are smaller when the flexible touch screenpanel is in a bent state than when the flexible touch screen panel is ina non-bent state.
 7. The flexible touch screen panel of claim 6, whereinthe flexible touch screen panel is capable of being bent such thatportions of the first surface face each other.
 8. The flexible touchscreen panel of claim 6, wherein the areas of first and second sensingcells formed on the first region are smaller than areas of the first andsecond sensing cells formed on the second regions.
 9. The flexible touchscreen panel of claim 6, wherein the first sensing cells and the secondsensing cells are disposed on the same layer.
 10. The flexible touchscreen panel of claim 9, wherein the first sensing cells areelectrically connected to each other by first connecting lines, and thefirst sensing cells and the first connecting lines are disposed ondifferent layers.